Fibrous synthetic material of



Patented Dec. 2, 1952 FIBROUS SYNTHETIC MATERIAL OF IMPROVED WHITENESS OR COLOR Douglas James Fry and John David Kendall, Ilford, England, assignors to Ilford Limited, Ilford, England, a British company No Drawing. Application January 9, 1950, Serial No. 137,67 3. In Great Britain January 14, 1949 9 Claims.

This invention relates to a process for the improvement of natural or synthetic fibrous materials hereinafter generically referred to as fibrous materials. Within this term is to be understood textile materials generally in the form of filaments, threads, yarns, woven or knitted fabrics, made of cotton, silk, wool, hemp or flax, or of synthetic materials such as regenerated cellulose, cellulose nitrate, cellulose acetate, cellulose propionate, cellulose butyrate and mixed cellulose esters as, for instance, cellulose acetatebutyrate and cellulose acetate-propionate, nylon, perlon and similar synthetic linear polyamides, vinyl derivatives such as vinyl esters, acetals, chlorides and other polymeric colloid materials including mixed polymers and interpolymers of vinyl derivatives and polymers of acrylic and methacrylic derivatives. Also included are natu ral fibrous materials such as wood pulp and synthetic fibrous materials made of any of the foregoing types of synthetic compounds not in tex- 'le form, e. g. paper, cardboard, felt and compacted synthetic fibres.

According to the present invention a process for improving fibrous materials and particularly for improving textiles made of nylon or cellulose acetate, comprises applying thereto a small quantity of a compound of the general formula:

wherein R1 and R2 are alkyl or oxyallryl groups, and R3 to Rm may be hydrogen atoms, or any of them may represent substituted groups such as alkyl, alkoxy, amino and substituted amino groups, or halogen atoms, and X is an acid radicle, which compound is colourless in ethyl alcoholic solution. By the term colourless in ethyl alcoholic solution is meant that a solution of the compound in ethyl alcohol has an absorption maximum not greater than 4000 A.

The preferred compounds according to this invention are those in which the absorption maximum is below 3900 A. and of these the compound in which some of R3 to R represent lower alkyl groups and the remainder are hydrogen atoms are preferred. The nature of the acid radicle X appears to be of little importance apart from its efiect on the solubility of the compounds. It may be halide or sulphate, but from the practical standpoint the p-toluene sulphonates are generally preferred as these have usually a satisfactory degree of solubility in water.

The following are examples of specific com- (7) 3:3-diethyl-6:6'-dimethyl oxacyanine pounds which may be employed according to the present invention:

(1) 3.3'-dimethyl oxacyanine iodide, 111. pt. 317 C. decomp., the corresponding methosulphate, m. pt 323 C. decomp.

(2) 3-methyl-3'-ethyl oxacyanine iodide, m. pt.

301 C. decomp.

(3) 3:3:6:6-tetramethyl oxacyanine iodide, m.

pt. 317 C. decomp.

(4) 3:3:5:5':6:6-hexamethyl oxacyanine bromide, m. pt. 322 C. decomp., the corresponding methosulphate, m. pt. 313 C. decomp. and the corresponding p-toluene sulphonate, m. pt. 320 C. decomp.

(5) 3:3'-diethyl-5:6-dimethyl oxacyanine iodide,

m. pt. 292 C. decomp.

(6) 3:3'-diethyl-5:6:5:6 tetramethyl oxacyanine iodide, m. pt. 311 C. decomp.

1odide, m. pt. 306 C. decomp.

(8) 3:3'-dimethyl-5:5-dichlor oxacyanine ptoluenesulphonate (m. pt. above 300 C.)

(9) 3:3':,5:5'tetramethyl oxacyanine bromide (in. pt. 298 C. with decomp.)

(l0) 3:3z5z5z6-pentamethyl oxacyanine p-toluene sulphonate (m. pt. 280 C. with decomp.)

(11) 3:3:5:6tetramethyl oxacyanine p-toluene sulphonate (111. pt. 314 C. with decomp.)

(12) 3:3-dimethyl-5-acetamino oxacyanine ptoluene sulphonate (m. pt. 283 C. with decomp.)

(l3) 3:3'-dimethyl 5-brornoxacyanine p-toluene sulphonate (m. pt. 298 C. with decomp.)

The compounds of the foregoing general for-- mula may be prepared by condensing a, quaternary salt of an appropriate z-methyl benzoxazole with a quaternary salt of an appropriate 2-a1- kylthio benzoxazole in the presence of a base such as pyridine.

Compounds of the foregoing general formula which are colourless, white or pale yellow have have been found to possess a strong fluorescence in daylight and a slightly less fluorescence in in.- candescent electric or similar light, and on application to fibrous materials they impart such duorescence to them. The fluorescence varies in colour between violet, pale blue and deep blue. The effect of applying these compounds to fibrous materials is to impart a degree of brilliance to them which is attractive and useful. Applied to materials which are allegedly white, but of which the whiteness has a slight tinge of yellow or brown, the compounds serve to kill the yellow or brown tinge so that the apparent whiteness of the materials is very appreciably enhanced. This application of the materials is of especial importance, and the present invention is therefore particularly concerned with. the app i ation of the compounds to such off-white fibrous materials.

3 Applied to dyed textile materials the compounds have the effect of improving the apparent purity of the colour.

The compounds of the present invention, being salts of organic bases, are more or less readily soluble according to their constitution in polar organic solvents such as lower alcohols, esters and ketones and are sufficiently soluble in water to permit their application to fibrous materials from aqueous solution. In aqueous solution they exhibit a remarkably non-selective affinity to the most varied types of fibres so that they can be applied from very dilute solution without the aid of auxiliary agents and Without having to be dispersed in finely divided form.

Very small quantities of the compounds are suflicient to achieve the desired improvement in the fibrous materials. Thus treatment of the materials with one of the said compounds, in water or an organic solvent, at a solution concentration of 1 part in 1000 to 1 part in 1,000,000 is usually satisfactory. In such aqueous concentration they are taken up readily on wool, cotton and regenerated cellulose fibres and, surprisingly, also on synthetic linear polyamide fibres such as nylon and perlon and, perhaps even more surprisingly, on fibres having a cellulose ester basis, e. g. cellulose acetate, and fibres with a polyvinyl and polyvinylene basis.

Optical bleaching agents or brightening agents which function by virtue of their inherent fluorescence are already known for application to fibrous materials. However, the previously known materials, where they have been applicable from aqueous solution, have had a restricted application to such materials as wool and cellulose fibres, and have been virtually useless for application to cellulose ester materials. Similarly there is no better known material which can be taken up from aqueous solution on to fibres of synthetic linear polyamides and which possess the practical requirements of fastness to light and to washing.

It is one of the principal features of the present invention that it provides for the first time optical bleaching agents which can be taken up from aqueous solution on to fibrous materials having a basis of cellulose esters or synthetic linear polyamide (nylon), and yields by such treatment products which are not only satisfactorily brightened but of which the brightening effect is satisfactorily fast both to light and to washing.

The fact that the compounds of the present invention can be taken up from aqueous solution on to cellulose ester fibres is the more surprising when it is appreciated that the commercial dyeing of these fibres in deep colours can only be satisfactorily achieved by the use of finely dispersed azo dyestuffs. For this reason these fibres could, up to now, only be satisfactorily brightened by the use of fine aqueous dispersions of water-insoluble blue-fiuorescing brightening agents. In contrast, the compounds of the present invention can be applied by a much simpler process and they yield products which are not only satisfactorily brightened and which have good fastness to washing, but which have, in particular, a degree of light-fastness greater than that hitherto obtained by the use of any of the usual brightening agents.

Because of their special properties, the compounds of the present invention fill a longstanding gap in the field of the optical bleaching of textiles. Their practical value in the field of 4 treating cellulose ester and synthetic linear polyamide fibres is remarkable and unexpected, and since, moreover, they have a substantially nonselective affinity for all types of fibres they present the additional practical advantage that they can be applied to mixed fibres, e. g. mixed fabrics of nylon or acetate silk with other textile fibres.

The effectiveness of the compounds of this invention varies to some extent, and of those listed above the compounds found most useful are numbers 4, 5, 6 and 11. From the economic standpoint numbers 6 and 11 are preferred since they can be made more cheaply and they have, in the form of their p-toluene sulphonate salts, a suificiently good solubility in water to make their application from that medium a sound commercial practice.

In the case of fibrous materials which are not in their natural state, the compounds of this invention may be applied thereto at any stage in the manufacture of such materials. Thus in the production of artificial filaments or fibres by the extrusion of colloid compositions, the oxacyanine compounds of this invention may be incorporated in such compositions before extrusion so that they are uniformly dispersed throughout the products.

Alternatively the fibrous materials may be treated with solutions of the compounds at any stage in the manufacture of the fibrous materials. Thus in the treatment of textile materials the compounds may be included in any of the liquids commonly employed for dyeing, dressing and the like.

In the case of paper and similar materials the oxacyanine compounds may be applied to the wood pulp or rag-fibre before such material is made into paper, or during the paper-making operation, or may be applied as a solution directly to the raw paper, or may be applied in a dressing composition, e. g. a baryta coating, applied to the paper.

The following examples serve to illustrate the invention but are not to be regarded as limiting it in any way:

Example 1 20 gm. of acetate silk skein are introduced at 50 C. into a dyebath containing 0.01 gm. 3 :3 :5 :5 6 6-hexamethyloxacyanine p-toluene sulphonate in 1,000 cc. water. The temperature is raised during 15 minutes to C. and kept at this temperature for a further 15 minutes. The skein is then rinsed with cold water and dried. The yarn so obtained exhibits in daylight a very good brightening effect which is characterised by good light fastness and fastness to washing.

Example 2 20 gm. of nylon cloth are introduced at 50 C. into a dyebath which contains 0.001 gm. 3:3 :5 B-tetramethyloxacyanine p-toluene sulphonate in 1,000 cc. water. The temperature is raised during 15 minutes to C. and kept at this temperature for a further 15 minutes. The cloth is then rinsed first with lukewarm, then with cold water and dried. The material so treated displays in daylight a beautiful brightening effect, which has Very good light fastness and good fastness to washing.

A similar result is obtained with 0.001 gm. 3:3 :5z5:6:6'-hexamethyloxacyanine p toluene sulphonate in place of the precedin brightening agent.

Example 3 20 gm. of perlon yarn are introduced at 50 G. into a dyebath containing 0.01 gm. 3:3 ::5:6:6- hexamethyloxacyanine p toluene sulphonate dissolved in 1,000 cc. of water, the temperature raised during minutes to 90 C. and kept for a quarter of an hour at this temperature. The yarn is then rinsed with cold water and dried. The yarn so treated displays in daylight a strong brightening compared with the untreated material. The optically bleached material has good fastness to washing andvery good light fastness.

Example 4 40 gm. bleached cotton is dipped into a dye liquor at 90 C. which contains 0.01 gm. 3:3:- 5:5':6:6' hexamethyloxacyanine p toluene sulphonate and 1 gm. Glaubers salt in 1,000 cc. water and treated for 15 minutes at this temperature. The material is then rinsed in cold water, centrifuged and dried by ironing. The material so treated has a strongly brightened effect in daylight. The optical brightening effect is sufficiently fast to wet conditions and has good fastness to light.

Example 5 30 gm. of a satin cloth prepared from acetate silk as warp and viscose crepe as weft are introduced at 40 G. into a dyebath which contains 0.01 gm. of 3:3:5:G-tetramethyloxacyanine p-toluene sulphonate and 1 gm. Glauber salts dissolved in 1,000 cc. water. The dyebath is warmed during 15 minutes to 70 C. and then maintained at this temperature for a further 15 minutes. The cloth is then rinsed with cold water and dried. The treated material viewed in daylight appears uniformly brightened. Similar results are obtained with unions of nylon and cotton.

Though these examples refer to only two specific compounds, it is to be understood that any others of the compounds listed above may be substituted therefor with results which differ only in degree.

What we claim is:

1. Nylon fabrics having adsorbed thereto a very small quantity of a compound of the general formula:

where R1 and R2 are selected from the class consisting of alkyl and oxyalkyl groups and R3 to R10 inclusive are selected from the class consisting of hydrogen atoms, halogen atoms and alkyl, alkoxy, amino and substituted amino groups, and X is an acid radicle, which compound is colourless in ethyl alcoholic solution.

2. Fibrous materials comprising fibres of synthetic linear poly-condensation products of the amide type having adsorbed thereto a compound of the general formula:

where R1 and R2 are selected from the class con sisting of alkyl and oxyalkyl groups and R3 to R10 inclusive are selected from the class consisting of hydrogen atoms, halogen atoms and alkyl alkoxy, amino and substituted amino groups, and X is an acid radicle, which compound is colourless in ethyl alcoholic solution.

3. Fibrous materials comprising fibres of synthetic linear poly-condensation products of the amide type having adsorbed thereto a compound of the general formula:

where R1 and R2 are selected from the class consisting of alkyl and oxyalkyl groups and R3 to Rm inclusive are selected from the class consisting of hydrogen atoms, halogen atoms and alkyl, alkoxy, amino and substituted amino groups, and X is an acid radicle, which compound in ethyl alcoholic solution has an absorption maximum below 3900 A.

4. Fibrous materials comprising synthetic linear polyamide fibres having adsorbed thereto an oxacyanine salt of which the benzene nuclei contain as sole substituents at most 2 lower alkyl groups.

5. Fibrous materials comprising synthetic linear polyamide fibres having adsorbed thereto an oxacyanine salt of which the benzene nuclei contain as sole substituents at most 2 methyl groups.

6. Fibrous materials comprising synthetic linear polyamide fibres having adsorbed thereto 3 :3 :5 :5 :6 :6'-hexamethyl oxacyanine p-toluene sulphonate.

7. Fibrous materials comprising synthetic linear polyamide fibres having adsorbed thereto 3:3:5:6 tetramethyl oxacyanine p-toluene sulphonate.

8. Nylon fabrics having adsorbed thereto 3:3:- 5:5':6:6'-hexamethyl oxacyanine p-toluene sulphonate.

9. Nylon fabrics having adsorbed thereto 3:3':5:6 tetramethyl oxacyanine p-toluene sulphonate.

DOUGLAS JAMES FRY. JOHN DAVID KENDALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,072,908 Schneider Mar. 9, 1937 2,108,485 Hamer Feb. 15, 1938 2,334,348 Miglarese Nov. 16, 1943 2,468,431 Eberhart Apr. 26, 1949 2,528,323 Thomas Oct. 31, 1950 FOREIGN PATENTS Number Country Date 522,672 Great Britain June 24, 1940 566,810 Great Britain Jan. 15, 1945 OTHER REFERENCES Geigy, Rayon Textile Monthly for September 1947, page 118 (502).

Landolt: Fluorescent Bleaching, American Dyestuff Reporter, April 18, 1949, pages 353-356. 

1. NYLON FABRICS HAVING ASSORBED THERETO A VERY SMALL QUANTITY OF A COMPOUND OF THE GENERAL FORMULA: 